In recent years in the development of computer technology, the alphanumeric keyboard has been augmented by input devices which are used to position the cursor on a monitor screen for selecting icons by the operation of a switch. The most common such input device is the mouse. Hardly a personal computer today is found without a mouse or other pointing device which allows the mouse or pointing device to control certain functions of the computer.
Anyone who has driven at night and noticed the bright reflection of the eyes of a distant animal in an otherwise dark visual field, has experienced the effectiveness of retroreflection. Retroreflection is the return of light, by an object or material, nominally back to the source.
The mouse, being a hand operated device used on the horizontal work surface near the keyboard and monitor, must be connected by a cable, which unfortunately, limits the range of the movement of the mouse. The cable, which supplies operating power to the mouse, also receives signals from the mouse about its position and user commands.
The mouse typically includes a ball, which rolls on a surface or mouse pad. The ball is coupled to optical chopper wheels within the mouse housing which respond to movement of the mouse to produce pulses of light representing mouse movement. This is all well-known conventional mouse technology.
Inside the mouse, electrical power, is converted to light by four light emitting diodes (LED""s), two each at two orthoginally-oriented chopper wheels. As the mouse is moved on a surface, the chopper wheels rotate in correspondence with the lateral or longitudinal components of motion of the mouse. Light is intermittently blocked by spokes of the chopper wheels, or projected through the holes in the chopper wheels, where it is detected by the photo detectors within the mouse and converted back to electrical signals representing mouse movement. Command signals are usually in the form of switch operations by the user. Mice heretofore have been electro/optical/mechanical devices.
It would be highly desirable to provide a mouse or other pointing device which performed the same functions but without a cable connection to the computer. Several attempts have been made to accomplish this objective but none have met wide success.
Some cordless mice have been developed which communicate with the computer with an infrared or radio signal generated in the mouse, similar to appliance remote controls; however, all have also been electro/optical/mechanical devices, in which internal batteries provide an electrical charge for a limited time before they must be recharged, interrupting use of the computer and inconveniencing the user. Further, batteries add weight to the mouse and increase the mass and inertia, causing fatigue to the computer user. While cordless mice eliminate the inconvenience and restrictions of a cord, they nevertheless are heavier, more complicated and more expensive than corded mice.
There also exists a continuing need for improved low cost optical systems which use a minimum of refractive elements, e.g., lenses or prisms. In connection with meeting the need of a low cost cordless purely reflective computer mouse, it is also an objective of this invention to produce a general purpose optical system with a mouse or pointing device or remote controller which is totally devoid of any internal power source such as a battery or poser supply lead wire and further free of any electronic components in the mouse, pointing device or remote controller.
The capability of this concept as described hereinafter, also serves to fill the continuing need for remote controllers for television sets VCR""s audio systems and the like. By incorporating the invention described herein, the need to provide and replace batteries is forever eliminated. Likewise all electronic or electrical components and electro mechanical elements are eliminated from the remote controller.
The subject of this invention is an optically retroreflective non-electrical mouse or pointing device which contains only a housing, the mouse ball, its rollers, and simple passive optical elements so that the only input to the mouse is light or an optical beam from the computer which the mouse intermittently reflects back to the computer where it is detected. The mobility of the mouse is limited only to an unobstructed line-of-sight path between the mouse and the light source typically in the base of the desktop or notebook computer. In principle, this invention is an optically retroreflective mouse.
The mouse of this invention contains standard light chopper wheels plus simple optical elements such as mirrors, retroreflectors, beamsplitters, filters, prisms, diffraction gratings, or lenses, some of which may be inexpensively molded into the mouse. Necessary mouse button operations may be accomplished by a simple shutter which permits a momentary flash of light to indicate actuation.
An object of this invention is a cordless opto/mechanical retroreflective computer mouse which does not contain any electronics or power sources.
Typically, optical instruments require precise alignment between all optical elements for proper operation. The cordless mouse and mouse controller of this invention, constitute both ends of an optical system for which it would seem that precise alignment of the mouse, relative to the computer, would be required in order to receive a return signal at the computer.
To solve this problem retroreflectors, rather than simple mirrors, are used in the mouse at the chopper wheels and mouse-button, because retroreflectors return light, nominally to the source, within a wide cone angle.
The send-receive optics on the mice and computers of this invention share the property of receiving and radiating light over a wide fan-shaped horizontal angle in the same space between the computer and mouse, but reducing the horizontal spread to essentially a collimated pencil beam within the computer and mouse which can be used by the prism, diffraction grating, etc. The angular position of this collimated white-light beam is shown in mice in the average, on-axis position as if coming from the mid-position relative to the mouse send-receive optics.
When the incident optical beam reaches the mouse off axis, the white-light beam which emerges out of the wide-angle send-receive optics in the mouse slightly angularly misaligned, although the angular misalignment is greatly reduced due to the nature of the wide-angle optics. Nevertheless, the amount that the optical paths in the mice are angularly shifted, is related to the horizontal magnification ratio of the relative to the computer.
The white light, after being spectrally separated in the mouse, varies its angular path, in the horizontal plane, and its incident angle on the retroreflectors at the button shutter and chopper wheels. The incident angle of light at the retroreflective is not predictable as being perpendicular to the retroreflector. Therefore, first surface mirrors are a poor choice to be used. Retroreflectors can retroreflect light over a fairly wide angle and can easily handle the modest incident angles used in the optical mice. By way of contrast, retroreflectors can easily reflect light within the modest incident angle and return that light along its incident path, out of the wide-angle optics of the mouse, which increase the angle to match the outside incident angle, and back to the computer.
One embodiment of this invention includes means for receiving broad-spectrum light from a source typically in the base of the computer or possibly a separate cabled mouse controller housing. Within the mouse, the received light is separated into multiple discrete wavelengths, or colors, and directed optically with mirrors at necessary positions, two each at two chopper wheels. The light is modulated, i.e., intermittently blocked or projected through holes in the chopper wheels, where it is retroreflected back through the optical system, out of the mouse and back to the computer. Color-specific photo detectors in the computer sense the presence or absence of the return signal (colored light of preselected wavelengths) and allow the computer to interpret the longitudinal and lateral movement of the mouse to move a cursor appropriately on the computer monitor, or to affect such other computer options.
All of the electronic components used with this mouse are located in the computer, or a separate mouse controller, and none are in the mouse, track ball or pointing device. The optical elements which serve as the light receptors preferably are shielded from interference from direct ambient light. One or more wide-angle lenses are typically located at the front corners of the computer to project and receive light pulses to and from the mouse. The light radiation from the computer is preferably produced by a broad-spectrum light source such as an incandescent lamp or a plurality of discrete wavelength light emitting diodes (LED""s) of, for example, five non-interfering wavelengths, and is irradiated over an area corresponding to the normal range of mouse movement. This area is termed the optical field of the computer.
Typically, four optical return signals are used for defining the X and Y positions of the mouse. In addition, one light signal is used for each mouse button. A one-button mouse returns a total of five optical signals. A two-button mouse provides six return signals, etc. The mouse button actuates a simple camera-type shutter, which is in the optical path of a discrete color, to allow a flash of that color to be retroreflected to the computer. The colors preferably should not be visible, typically being produced with a filtered incandescent lamp or infrared and/or ultraviolet LED""s or laser diodes emitting radiation outside of the visible spectrum.
Return light from the mouse enters the wide-angle lens acting as receiving means in the base of the computer and is directed to a number of photo detectors each sensitive to a selected color or of a corresponding LED. Each detected return radiation sequence constitutes an optical command signal for the computer which becomes an optically controlled computer.
The components of the mouse preferably are oriented at 45 with respect to the longitudinal axis of the mouse to work for both right and left-handed people. Cylindrical lenses are used on the outside of the mouse and the computer to receive and project light in a flat fan shape, across the surface where the mouse will be used. The light sources in the computer themselves can be pulsed with unique signatures to help differentiate the return signals from each other and ambient room light (optical noise).
The connection between the mouse and the computer is optical, requiring only line of sight communication. Basically, the computer serves to emit light to, and to detect retroreflected light from, the mouse. The mouse serves to modulate light by returning, or not returning the light back to the computer by interrupting or chopping specific colors in response to the direction and extent of mouse movement as well as manual operation of the mouse button.
Various techniques are possible in both the computer and mouse for achieving their assigned functions. From an appearance point of view, it may be desirable, but not essential, to have the computer and mouse communicate with non-visible forms of energy, for example, in the infrared band. However, to facilitate description, white light and visible colors will be used to describe the operation of the mouse.
The light source can be a broad spectral source such as an incandescent lamp or multiple LED""s of discrete colors. In both the mouse and detector portion of the computer the combined broad-spectrum light signal can be spectrally separated with a variety of techniques, such as:
a. beamsplitting white light with a series of 45 dichroic cube prism or plate-type beamsplitters;
b. reflecting white light off of a diffraction grating;
c. transmitting white light through a transmission diffraction grating;
d. transmitting white light through a triangular prism, to be refracted into the spectrum; and
e. transmitting white light through a variable interference filter in a spectrum of colors.
In all cases listed above, where necessary, narrow bandpass optical filters can be used in the separated optical paths, in the mouse and in the detection area of the computer, to optically isolate the desired color. This allows detectors to provide typically five discrete signals in response to mouse operation.
In addition, a cylindrical negative lens or cylindrically convexed mirror can be used to spread the fan-angle of the spectrum to more easily intercept individual colors. It is also possible following the teaching of this invention to achieve a cordless optical mouse or pointing device which is not only free of electrical or electronic parts but free of any refractive optical elements. This is achieved in part through the use of wide angle cylindrical reflectors used off axis in pairs having the effect of narrowing the angle of incoming light into a virtual zero angle beam which is the equivalent of an optical slit. This combination allows the wide-angle incoming reflected beams to pass through a narrow lensless opening or window in the housing.
In the field of remote controlled electronic apparatus, the same concept as applied to computer mice and pointing devices is possible, as well. All electronics for the remote control of this invention are contained in the electronics housing such as a VCR or television set. In contrast to most remote control systems in use today for electronic systems which use infrared optical signaling, in this invention the source of the optical signal is in the electronic equipment being controlled itself, and it employs not only the source of the optical signal but also the receptors of the retroreflected and modulated optical signal from the remote controller.
In its simplest form the modulation within the remote controller is in the form of chopping or interrupting the beam before retroreflection. In other cases it involves optically filtering the incident light from the electronic equipment with the spectrum-altered retroreflected beam constituting the control signal from the remote controller.
This invention is best illustrated as a controller for a VCR system in which the remote controller has the same general appearance as a state-of-the-art infrared controller for a VCR.
A variety of conventional operating controls are located on one face for operation by the user with the front end of the controller facing the electronic equipment to be controlled and in the field of the radiated optical signal from the electronic equipment housing. Within the housing of the remote controller is a retroreflective optical system and a series of modulators, one for each of the functions of the remote controller. In one embodiment, the modulators comprise a series of leaf spring fingers, which are movable in response to the operation of a different control on the top face of the remote controller. The leaf-spring fingers act as opto-mechanical light shutters.
The signal source of the system, contained in the electronic equipment housing, or optionally in a separate housing, includes a number of optical signal sources such as an array of LEDs which are directed either out of a window in the housing of the equipment or, preferably directed at the input end of one or more optical fibers which convey the light generated by the LEDs to a selected surface of the equipment housing. Preferably the light output optical fiber or window in the equipment housing is located on the surface of the equipment housing facing the expected location of the user. A second optical fiber or series of return signal optical fibers is located immediately adjacent to the light output fibers for receiving retroreflected and modulated light beams from the remote controller. Return signals are reflected through beam spreading optics to a series of light receptors, each one corresponding to the sight source LEDs to provide control signals corresponding to each function to be controlled.
It is within the contemplation of this invention that a single broad-band light source is used and the modulation by each control is to modify that emitted light beam, for example, by selective filtration of the wavelengths present in the retroreflected beam to constitute the control function and the receptor or receptors within the equipment housing responds to the different wavelengths present in the retroreflected beam to detect a control signal.